Room

I was expecting the entirety of this story to take place in the room, with maybe a rescue at the very end. Instead, it does a brilliant thing by having the escape less than halfway through the book and then dealing with the much more interesting implications of adapting back into society when your entire worldview up until then has consisted of a 11x11 foot shed.

It definitely kept me reading in long stretches and I always wanted to see what would happen next.